Meet the shy, invasive Joro spider riding winds along the East Coast
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A Joro spider in Japan in 2022. Photo: David Madison/Getty Images
An invasive but extremely "shy" and harmless spider that can float on the breeze could arrive in new parts of the East Coast later this summer.
Why it matters: Since first appearing in the U.S. around 2013 and 2014, the Joro spider, native to Japan and other parts of Asia, has slowly expanded across the Southeast and could establish themselves across the East Coast over the coming years, researchers say.
Zoom out: Fortunately, they don't appear to significantly affect local food webs or ecosystems.
- In fact, they may thrive in the Eastern U.S. not by out competing native species for resources but by weathering colder temperatures better than their native relatives.
How it works: Trichonephila clavata, also called Joro spiders, are "urban tolerant" members of the orb-weavers family and spin massive golden webs on houses, in power lines, trees and many other structures.
- It's a common misconception that Joro spiders can fly. They instead enter new areas by releasing lines of silk and "parachuting" or "ballooning" on winds, as do a lot of other arachnids, according to the Missouri Department of Conservation.
- Female Joros are yellow, blue-black and red and can grow to have a leg span up to 4 inches long, while males are smaller and brown.
Zoom in: Though they may look intimidating and are technically venomous (as are most spiders), they are likely harmless if left alone.
- Research suggests they are rather timid and, like most spiders, their fangs likely aren't large enough to pierce human skin.
The big picture: Experts are divided on whether people should kill Joro spiders, or invasive species in general, or if they should be left alone.
- One danger of killing invasive species like Joro spiders is accidentally doing harm to similar-looking native insects, like the black and yellow garden spider, the banana spider or the banded garden spider.
- The Joro spider is just one of the thousands of invasive species that have established themselves across the U.S., most of which were introduced because of unintentional human activity, per the National Park Service.
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